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12#include <linux/init.h>
13#include <linux/module.h>
14#include <linux/kernel.h>
15#include <linux/platform_device.h>
16#include <linux/rtc.h>
17#include <linux/io.h>
18#include <linux/bcd.h>
19
20#define DRV_NAME "rtc-ds1302"
21#define DRV_VERSION "0.1.1"
22
23#define RTC_CMD_READ 0x81
24#define RTC_CMD_WRITE 0x80
25
26#define RTC_ADDR_RAM0 0x20
27#define RTC_ADDR_TCR 0x08
28#define RTC_ADDR_YEAR 0x06
29#define RTC_ADDR_DAY 0x05
30#define RTC_ADDR_MON 0x04
31#define RTC_ADDR_DATE 0x03
32#define RTC_ADDR_HOUR 0x02
33#define RTC_ADDR_MIN 0x01
34#define RTC_ADDR_SEC 0x00
35
36#ifdef CONFIG_SH_SECUREEDGE5410
37#include <asm/rtc.h>
38#include <mach/secureedge5410.h>
39
40#define RTC_RESET 0x1000
41#define RTC_IODATA 0x0800
42#define RTC_SCLK 0x0400
43
44#define set_dp(x) SECUREEDGE_WRITE_IOPORT(x, 0x1c00)
45#define get_dp() SECUREEDGE_READ_IOPORT()
46#define ds1302_set_tx()
47#define ds1302_set_rx()
48
49static inline int ds1302_hw_init(void)
50{
51 return 0;
52}
53
54static inline void ds1302_reset(void)
55{
56 set_dp(get_dp() & ~(RTC_RESET | RTC_IODATA | RTC_SCLK));
57}
58
59static inline void ds1302_clock(void)
60{
61 set_dp(get_dp() | RTC_SCLK);
62 set_dp(get_dp() & ~RTC_SCLK);
63}
64
65static inline void ds1302_start(void)
66{
67 set_dp(get_dp() | RTC_RESET);
68}
69
70static inline void ds1302_stop(void)
71{
72 set_dp(get_dp() & ~RTC_RESET);
73}
74
75static inline void ds1302_txbit(int bit)
76{
77 set_dp((get_dp() & ~RTC_IODATA) | (bit ? RTC_IODATA : 0));
78}
79
80static inline int ds1302_rxbit(void)
81{
82 return !!(get_dp() & RTC_IODATA);
83}
84
85#else
86#error "Add support for your platform"
87#endif
88
89static void ds1302_sendbits(unsigned int val)
90{
91 int i;
92
93 ds1302_set_tx();
94
95 for (i = 8; (i); i--, val >>= 1) {
96 ds1302_txbit(val & 0x1);
97 ds1302_clock();
98 }
99}
100
101static unsigned int ds1302_recvbits(void)
102{
103 unsigned int val;
104 int i;
105
106 ds1302_set_rx();
107
108 for (i = 0, val = 0; (i < 8); i++) {
109 val |= (ds1302_rxbit() << i);
110 ds1302_clock();
111 }
112
113 return val;
114}
115
116static unsigned int ds1302_readbyte(unsigned int addr)
117{
118 unsigned int val;
119
120 ds1302_reset();
121
122 ds1302_start();
123 ds1302_sendbits(((addr & 0x3f) << 1) | RTC_CMD_READ);
124 val = ds1302_recvbits();
125 ds1302_stop();
126
127 return val;
128}
129
130static void ds1302_writebyte(unsigned int addr, unsigned int val)
131{
132 ds1302_reset();
133
134 ds1302_start();
135 ds1302_sendbits(((addr & 0x3f) << 1) | RTC_CMD_WRITE);
136 ds1302_sendbits(val);
137 ds1302_stop();
138}
139
140static int ds1302_rtc_read_time(struct device *dev, struct rtc_time *tm)
141{
142 tm->tm_sec = bcd2bin(ds1302_readbyte(RTC_ADDR_SEC));
143 tm->tm_min = bcd2bin(ds1302_readbyte(RTC_ADDR_MIN));
144 tm->tm_hour = bcd2bin(ds1302_readbyte(RTC_ADDR_HOUR));
145 tm->tm_wday = bcd2bin(ds1302_readbyte(RTC_ADDR_DAY));
146 tm->tm_mday = bcd2bin(ds1302_readbyte(RTC_ADDR_DATE));
147 tm->tm_mon = bcd2bin(ds1302_readbyte(RTC_ADDR_MON)) - 1;
148 tm->tm_year = bcd2bin(ds1302_readbyte(RTC_ADDR_YEAR));
149
150 if (tm->tm_year < 70)
151 tm->tm_year += 100;
152
153 dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
154 "mday=%d, mon=%d, year=%d, wday=%d\n",
155 __func__,
156 tm->tm_sec, tm->tm_min, tm->tm_hour,
157 tm->tm_mday, tm->tm_mon + 1, tm->tm_year, tm->tm_wday);
158
159 return rtc_valid_tm(tm);
160}
161
162static int ds1302_rtc_set_time(struct device *dev, struct rtc_time *tm)
163{
164
165 ds1302_writebyte(RTC_ADDR_SEC, ds1302_readbyte(RTC_ADDR_SEC) | 0x80);
166
167 ds1302_writebyte(RTC_ADDR_SEC, bin2bcd(tm->tm_sec));
168 ds1302_writebyte(RTC_ADDR_MIN, bin2bcd(tm->tm_min));
169 ds1302_writebyte(RTC_ADDR_HOUR, bin2bcd(tm->tm_hour));
170 ds1302_writebyte(RTC_ADDR_DAY, bin2bcd(tm->tm_wday));
171 ds1302_writebyte(RTC_ADDR_DATE, bin2bcd(tm->tm_mday));
172 ds1302_writebyte(RTC_ADDR_MON, bin2bcd(tm->tm_mon + 1));
173 ds1302_writebyte(RTC_ADDR_YEAR, bin2bcd(tm->tm_year % 100));
174
175
176 ds1302_writebyte(RTC_ADDR_SEC, ds1302_readbyte(RTC_ADDR_SEC) & ~0x80);
177
178 return 0;
179}
180
181static int ds1302_rtc_ioctl(struct device *dev, unsigned int cmd,
182 unsigned long arg)
183{
184 switch (cmd) {
185#ifdef RTC_SET_CHARGE
186 case RTC_SET_CHARGE:
187 {
188 int tcs_val;
189
190 if (copy_from_user(&tcs_val, (int __user *)arg, sizeof(int)))
191 return -EFAULT;
192
193 ds1302_writebyte(RTC_ADDR_TCR, (0xa0 | tcs_val * 0xf));
194 return 0;
195 }
196#endif
197 }
198
199 return -ENOIOCTLCMD;
200}
201
202static struct rtc_class_ops ds1302_rtc_ops = {
203 .read_time = ds1302_rtc_read_time,
204 .set_time = ds1302_rtc_set_time,
205 .ioctl = ds1302_rtc_ioctl,
206};
207
208static int __init ds1302_rtc_probe(struct platform_device *pdev)
209{
210 struct rtc_device *rtc;
211
212 if (ds1302_hw_init()) {
213 dev_err(&pdev->dev, "Failed to init communication channel");
214 return -EINVAL;
215 }
216
217
218 ds1302_reset();
219
220
221 ds1302_writebyte(RTC_ADDR_RAM0, 0x42);
222 if (ds1302_readbyte(RTC_ADDR_RAM0) != 0x42) {
223 dev_err(&pdev->dev, "Failed to probe");
224 return -ENODEV;
225 }
226
227 rtc = rtc_device_register("ds1302", &pdev->dev,
228 &ds1302_rtc_ops, THIS_MODULE);
229 if (IS_ERR(rtc))
230 return PTR_ERR(rtc);
231
232 platform_set_drvdata(pdev, rtc);
233
234 return 0;
235}
236
237static int ds1302_rtc_remove(struct platform_device *pdev)
238{
239 struct rtc_device *rtc = platform_get_drvdata(pdev);
240
241 rtc_device_unregister(rtc);
242 platform_set_drvdata(pdev, NULL);
243
244 return 0;
245}
246
247static struct platform_driver ds1302_platform_driver = {
248 .driver = {
249 .name = DRV_NAME,
250 .owner = THIS_MODULE,
251 },
252 .remove = ds1302_rtc_remove,
253};
254
255static int __init ds1302_rtc_init(void)
256{
257 return platform_driver_probe(&ds1302_platform_driver, ds1302_rtc_probe);
258}
259
260static void __exit ds1302_rtc_exit(void)
261{
262 platform_driver_unregister(&ds1302_platform_driver);
263}
264
265module_init(ds1302_rtc_init);
266module_exit(ds1302_rtc_exit);
267
268MODULE_DESCRIPTION("Dallas DS1302 RTC driver");
269MODULE_VERSION(DRV_VERSION);
270MODULE_AUTHOR("Paul Mundt, David McCullough");
271MODULE_LICENSE("GPL v2");
272
